Water heater with high efficiency baffles

ABSTRACT

A water heater for exchanging heat between hot gasses and water within the water heater. The water heater includes a water tank, a conduit for allowing flow of the gasses therethrough, the conduit extending through the tank and promoting heat exchange between the gasses and water in the tank, and a baffle extending within the conduit for affecting the flow of the gasses. The baffle includes a sheet bent in a zig-zag manner and having a number of plate sections. Each plate section has a through-flow portion allowing the gasses to flow therethrough. The sheet also has a number of first bends and a number of second bends, the first bends alternating with the second bends such that each plate section is defined between one first bend and one second bend.

BACKGROUND

The present invention relates to a water heater including a water tank and a conduit for hot gasses in heat exchange relationship with water within the tank.

SUMMARY

In one aspect, the invention provides a water heater for exchanging heat between hot gasses and water within the water heater. The water heater includes a water tank, a conduit for allowing flow of the gasses therethrough, the conduit extending through the tank and promoting heat exchange between the gasses and water in the tank. The water heater also includes a baffle extending within the conduit for affecting the flow of the gasses. The baffle includes a sheet bent in a zig-zag manner and having a number of plate sections. Each plate section has a through-flow portion allowing the gasses to flow therethrough. The sheet also has a number of first bends and a number of second bends. The first bends alternate with the second bends such that each plate section is defined between one first bend and one second bend.

In another aspect, the invention provides a water heater including a water tank, a device for producing heated gasses, and a conduit through which the heated gasses flow in a direction of gas flow. The conduit extends through the tank and promotes heat transfer between the gasses and water in the tank. The water heater also includes a baffle extending within the conduit for increasing the heat transfer between the gasses and the water. The baffle includes a sheet of material bent in a zig-zag manner to form a plurality of sheet sections. Each section extends in a different direction from adjacent sections, and each section has therein a flow opening that is out of alignment in the direction of gas flow with the flow openings in adjacent sections, such that gasses passing through a flow opening in a section must change direction to pass through the flow opening in the adjacent section.

In another aspect, the invention provides a method of manufacturing a water heater. The method includes providing a water heater having a water tank, a device for producing heated gasses, and a conduit through which the heated gasses flow in a direction of gas flow, the conduit extending through the tank. The method also includes providing a substantially planar sheet of material, bending the sheet of material in a zig-zag manner to form a plurality of substantially planar sheet sections, each section extending in a different direction from adjacent sections, and forming each section with a flow opening. The method also includes placing the baffle within the conduit so that each flow opening is out of alignment in the direction of gas flow with the flow openings in adjacent sections, such that gasses passing through a flow opening in a section must change direction to pass through the flow opening in the adjacent section.

In another aspect, the invention provides a water heater for exchanging heat between hot gasses and water within the water heater. The water heater includes a water tank, and a conduit for allowing flow of the gasses therethrough. The conduit extends vertically through the tank and promotes heat exchange between the gasses and water in the tank. The water heater also includes a baffle extending within the conduit for affecting the flow of the gasses. The baffle is operable to create a swirl-type flow of gasses through the conduit and includes a sheet bent in a zig-zag manner. The sheet has a number of plate sections, each plate section having a through-flow portion allowing the gasses to flow therethrough. The sheet also has a number of first bends and a number of second bends, the first bends alternating with the second bends such that each plate section is defined between one first bend and one second bend. All of the first bends and the second bends define substantially equal angles between adjacent plate sections, the angles being between about 50 degrees and about 80 degrees. The through-flow portion of one plate section is adjacent to one of the first bend and the second bend, and the through-flow portion of an adjacent plate section is adjacent to the other of the first bend and the second bend.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary water heater including a baffle according to one embodiment of the present invention.

FIG. 2 is a perspective view of the baffle shown in FIG. 1.

FIG. 2A is a detailed view of the baffle shown in FIG. 2.

FIG. 3 is a view of a plate for forming the baffle shown in FIG. 1.

FIG. 4 is a perspective view of a baffle according to another embodiment of the present invention.

FIG. 5 is a view of a plate for forming the baffle shown in FIG. 4.

FIG. 6 is an elevation view of the baffle shown in FIG. 1.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.

FIGS. 1, 2 and 6 illustrate a baffle 10 for a water heater according to one embodiment of the present invention. FIG. 1 illustrates an exemplary water heater 15 including the baffle 10. More particularly, the water heater 15 includes a base pan 20, a tank 25 supported by the base pan 20 and containing water, an insulating jacket 30 surrounding the tank 25, a control system 35, a burner 40 disposed in a combustion chamber 45 beneath the tank 25, a water inlet pipe 50, a water outlet pipe 55, and a flue system 60 including a flue tube 65 and the baffle 10 within the flue tube 65. The flue tube 65 has a longitudinal axis 68. During operation of the water heater 15, gas fuel is provided to the burner 40 through a conduit 70. Products of combustion or hot gasses flow up through the flue tube 65 and heat the water through the wall of the flue tube 65. Other constructions of the water heater also fall within the scope of the invention. While the water heater 15 is a storage- or tank-type water heater, in other constructions the water heater can be an instantaneous- or tankless-type water heater.

With particular reference to the flue system 60 illustrated in FIG. 1, a hanger or cross-bar 85 supports the baffle 10 within the flue tube 65. However other suitable means to support the baffle 10 fall within the scope of the invention. The baffle 10 extends longitudinally within the flue tube 65 to affect the flow of the hot gasses (further explained below). In the illustrated construction, the baffle 10 is positioned within the flue tube 65 to leave a space 90 between the lower end of the baffle 10 and the lower end of the flue tube 65. For example, the space 90 can facilitate mounting the flue tube 65 and baffle 10 on a glass coating machine that coats the inside and outside of the flue tube 65 and the baffle 10 with a protective glass coating to resist degradation of the flue tube 65 and baffle 10. Because the baffle 10 is recessed with respect to the lower end of the flue tube 65, the baffle 10 is less likely to be overheated by extreme temperatures in the combustion chamber 45. The space 90 may be, for example, about three inches in length but such length may vary based on manufacturing parameters.

According to one construction of the present invention, the baffle 10 is manufactured from a relatively flat plate or sheet of material. For example, the manufacturing process of the baffle 10 can include stamping or cutting the material to form a sheet 95 as shown in FIG. 3. In the illustrated construction, the sheet 95 has a number of plate sections 100, each plate section 100 forming an oval or ellipsoid shape, with a cut-out or flow opening 110, as described below. The sheet 95 can be manufactured of mild (i.e., low carbon) steel, stainless steel, Inconel, nickel alloy, or other suitable materials. It is to be understood that other processes and/or methods of processing a material to form the sheet 95 fall within the scope of the invention.

With reference to FIG. 3, the sheet 95 extends longitudinally forming a succession of substantially planar plate sections 100 along a reference axis 102. The sheet 95 also includes a number of bend portions 105, with each bend portion 105 formed between two adjacent plate sections 100 and defined by a relatively narrow portion of the sheet 95 along the axis 102. During a manufacturing process of the baffle 10 (see FIG. 2), the sheet 95 is preferably bent or deformed at the bend portions 105 in an accordion-like or zig-zag manner. More particularly, the baffle 10 includes alternating first bends 125 and second bends 130. The first bends 125 and second bends 130 are formed at the bend portions 105 of the sheet 95. For the purposes of description only, the terms “first bend” and “second bend” refer to the two directions in which the sheet 95 is bent at the bend portions 105. However, it is within the scope of the invention to bend or deform the sheet 95 differently than shown in FIGS. 1-3 and 6.

Plate sections 100 defining the first bends 125 and second bends 130 define an angle therebetween based on heat exchange requirements, such as the type of water heater. The magnitude of the angle formed at the first bends 125 is substantially the same with respect to the magnitude of the angle formed at the second bends 130. For a storage type water heater (e.g., water heater 15), the angle between adjacent plate sections 100 is approximately between 62 and 75 degrees. More preferably, the angle between adjacent plate sections 100 is about 70 degrees. For instantaneous water heaters, the angle between adjacent plate sections 100 is approximately between 52 and 65 degrees. More preferably, the angle between adjacent plate sections 100 is about 60 degrees. It is to be understood that other angles defined by adjacent plate sections 100 fall within the scope of the invention and are dependent on design characteristics, such as heat exchange requirements. For example, an alternate construction of the baffle 10 can include plate sections 100 forming different angles therebetween at different sections of the baffle 10 to allow a faster (or slower) gas flow through the conduit 65, thus adjusting heat exchange rates at different sections of the conduit 65.

Each plate section 100 includes an approximately oval or ellipsoid shape mainly defined by an outer edge 108. The ellipsoid shape of each plate section 100 allows the baffle 10 to snugly fit within the flue tube 65, which generally has a circular cross-section. Each plate section 100 includes a through-flow portion (also identified as a flow opening) 110, as mentioned above, defined by a first edge 115 and by a second edge 120. The through-flow portions 110 are designed to allow hot gasses therethrough during operation of the water heater 15. As shown in FIGS. 1 and 2, each plate section 100 has its through-flow portion 110 out of alignment in the direction of gas flow (upward in the drawings) with respect to the through-flow portions 110 in adjacent plate sections 100, such that gasses passing through a through-flow portion 110 in a plate section 110 must change direction to pass through the through-flow portion 110 in the adjacent plate section 110.

The first edge 115 and the second edge 120 are each formed as a relatively straight cut-out or line. More particularly, the first edge 115 and the second edge 120 form a sector having an included angle of about 90 degrees. In addition, the first edge 115 of one plate section 100 is substantially parallel to the first edge 115 of an adjacent plate section 100. Also, the second edge 120 of one plate section 100 is substantially parallel to the axis 102 and to the second edge 120 of an adjacent plate section 100. Other constructions of the sheet 95 can include through-flow portions having different shapes.

In the construction illustrated in FIGS. 2 and 6, the baffle 10 is designed to fit within the flue tube 65 such that the outer edges 108 of the plate sections 100 and the bend portions 105 (forming first bends 125 and second bends 130) contact or are very close to the inner wall of the flue tube 65. As a consequence, the baffle 10 regulates and/or affects the flow of the hot gasses generated in the combustion chamber 45. For example, the through-flow portions 110 of adjacent plate sections 100 are offset from one another (e.g., offset by 180 degrees), thus allowing the baffle 10 to create a flow of the hot gasses in a swirl pattern 135. In addition, the apertures defined by the through-flow portions 110 and the flue tube 65 positively affect the flow rate of the hot gasses therethrough.

With respect to FIGS. 2 and 2A, each plate section 100 can also be described as having a front portion and a rear portion, a right portion and a left portion, and an upper portion and a lower portion to define the position of the through-flow portions 110. In the illustrated construction, it can be observed that any two adjacent plate sections 100 are joined by either a first bend 125 or a second bend 130. If the through-flow portion 110 of one plate section 100 is formed adjacent the first bend 125, the through-flow portion 110 of an adjacent plate section 100 is formed adjacent the second bend 130, and vice versa.

Still with reference to FIGS. 2 and 2A, all plate sections 100 have their through-flow portions 110 in the same one of the upper portion and the lower portion. In the illustrated construction, each through-flow portion 110 is in the lower portion of the plate section 100, but they could be in the upper portions. Another characteristic of the baffle 10 is that if the through-flow portion 110 of one plate section 100 is in the front portion, the through-flow portion 110 of an adjacent plate section 100 is in the rear portion, and vice versa. Yet another characteristic of the baffle 10 is that if the through-flow portion 110 of one plate section 100 is in the right portion, the through-flow portion 110 of an adjacent plate section 100 is in the left portion, and vice versa.

The baffle 10 can be viewed still another way. Each of the first bends 125 defines a line, and each of the second bends 130 defines a line parallel to the lines of the first bends and parallel to the lines of other second bends. The lines of the first bends 125 define a first plane 150 (FIG. 6), and the lines of the second bends 130 define a second plane 155. The first plane 150 is substantially parallel to the second plane 155 and parallel to the axis 68 of the flue tube 65. FIG. 6 also shows that the planes defined by every other plate section 100 are substantially parallel.

FIGS. 4 and 5 illustrate a baffle 200 that is another embodiment of the present invention. The baffle 200 has many features in common with the baffle 10, and common elements have been given the same reference numerals.

Each plate section 100 of the baffle 200 includes a half-oval or half elliptical portion 223, mainly defined by arcuate outer edges 225, and an elongated portion 230. The outer edges 225 of the portion 223 are designed to contact the inner-surface of the flue tube 65. Each plate section 100 also includes a first through-flow portion 233 and a second through-flow portion 235 such that the elongated portion 230 is defined therebetween. The first through-flow portion 233 is defined by generally perpendicular first and second edges 240 and 245. Similarly, the second through-flow portion 235 is defined by generally perpendicular-third and fourth edges 250 and 255. In the illustrated construction, the second edge 245 and the fourth edge 255 are substantially parallel to one another, and the first edge 240 and the third edge 250 are collinear and substantially perpendicular to the axis 68.

Similar to the embodiment shown in FIGS. 2 and 2A, each plate section 100 can be described as having an upper portion and a lower portion. In the illustrated construction, the through-flow portions 233, 235 are in the lower portion of each plate section 100. The through-flow portions 233, 235 could alternatively be in the upper portion of each plate section 100.

In other alternative constructions (not shown), the plate sections can have other numbers of flow-through portions, and the flow-through portions can have other shapes.

Various features and advantages of the invention are set forth in the following claims. 

1. A water heater for exchanging heat between hot gasses and water within the water heater, the water heater comprising: a water tank: a conduit for allowing, flow of the gasses therethrough, the conduit extending through the tank and promoting heat exchange between the gasses and water in the tank; and a baffle extending within the conduit for affecting the flow of the gasses, the baffle including a sheet bent in a zig-zag manner and having a number of plate sections, each plate section having a through-flow portion allowing the gasses to flow therethrough, the sheet also having a number of first bends and a number of second bends, the first bends alternating with the second bends such that each plate section is defined between one first bend and one second bend.
 2. The water heater of claim 1, wherein the baffle is operable to create a swirl-type flow of gasses through the conduit.
 3. The water heater of claim 1, wherein the through-flow portion of one plate section is adjacent to one of the first bend and the second bend, and the through-flow portion of an adjacent plate section is adjacent to the other of the first bend and the second bend.
 4. The water heater of claim 1, wherein each plate section includes an upper portion and a lower portion, the through-flow portion of all plate sections being adjacent to the same one of the upper portion and the lower portion.
 5. The water heater of claim 1, wherein each plate section includes a front portion and a rear portion, the through-flow portion of one plate section being adjacent to one of the front portion and rear portion, and the through-flow portion of another plate section adjacent to the one plate section being adjacent to the other of the front portion and rear portion.
 6. The water heater of claim 1, wherein each plate section includes a right portion and a left portion, the through-flow portion of one plate section being in one of the right portion and the left portion, and the through-flow portion of an adjacent plate section being in the other of the right portion and the left portion.
 7. The water heater of claim 1, wherein the baffle is oriented such that the first bends are aligned on a first plane and the second bends are aligned on a second plane, the first plane being substantially parallel to the second plane.
 8. The water heater of claim 1, wherein each of the first bends defines a line along which the bend is formed, the line defined by one first bend being substantially parallel to the line defined by another first bend.
 9. The water heater of claim 1, wherein each of the first bends defines a line along which the first bend is formed and each of the second bends defines a line along which the second bend is formed, the line defined by the first bends being substantially parallel to the lines defined by the second bends.
 10. The water heater of claim 1, wherein each plate section defines a plane, the planes defined by every other plate section being substantially parallel to one another.
 11. The water heater of claim 1, wherein the through-flow portion of each plate section is defined by substantially perpendicular first and second edges of the plate section, with the first edges of all plate sections being substantially parallel and the second edges of all plate sections being substantially parallel.
 12. The water heater of claim 1, wherein the conduit is oriented vertically.
 13. The water heater of claim 1, wherein all of the first and second bends define substantially equal angles between adjacent plate sections.
 14. The water heater of claim 13, wherein the angles are between about 50 degrees and about 80 degrees.
 15. The water heater of claim 14, wherein the angles are about 70 degrees.
 16. The water heater of claim 13, wherein the water heater is a storage-type water heater and wherein the angles are between about 62 degrees and about 75 degrees.
 17. The water heater of claim 13, wherein the water heater is an instantaneous water heater and wherein the angles are between about 52 degrees and about 65 degrees.
 18. The water heater of claim 1, wherein each plate section has a second through-flow portion.
 19. A water heater comprising: a water tank; a device for producing heated gasses; a conduit through which the heated gasses flow in a direction of gas flow, the conduit extending through the tank and promoting heat transfer between the gasses and water in the tank; and a baffle extending within the conduit for increasing the heat transfer between the gasses and the water, the baffle including a sheet of material bent in a zig-zag manner to form a plurality of sheet sections, each section extending in a different direction from adjacent sections, and each section having therein a flow opening that is out of alignment in the direction of gas flow with the flow openings in adjacent sections, such that gasses passing through a flow opening in a section must change direction to pass through the flow opening in the adjacent section.
 20. The water heater of claim 19, wherein the conduit is generally circular in cross-section, and wherein each section is defined by a generally elliptical shape.
 21. The water heater of claim 20, wherein the conduit has a longitudinal axis, and wherein the flow openings of adjacent sections are offset approximately 180 degrees about the axis, causing a swirling flow of gasses through the conduit.
 22. The water heater of claim 21, wherein the conduit extends generally vertically and has a lower end, and wherein the device for producing heated gas includes a burner beneath the lower end of the conduit.
 23. The water heater of claim 22, wherein each section extends at an angle between approximately 27 to 38 degrees relative to horizontal.
 24. The water heater of claim 20, wherein each flow opening defines a sector having an included angle of approximately 90 degrees.
 25. The water heater of claim 19, wherein each section includes a second flow opening such that gasses passing through the flow opening and the second flow opening in one section must flow in a zig-zag direction to pass through the flow opening and the second flow opening in the adjacent section.
 26. A method of manufacturing a water heater comprising: providing a water heater having a water tank, a device for producing heated gasses, and a conduit through which the heated gasses flow in a direction of gas flow, the conduit extending through the tank; providing a substantially planar sheet of material; bending the sheet of material in a zig-zag manner to form a plurality of substantially planar sheet sections, each section extending in a different direction from adjacent sections; forming each section with a flow opening; and placing the baffle within the conduit so that each flow opening is out of alignment in the direction of gas flow with the flow openings in adjacent sections, such that gasses passing through a flow opening in a section must change direction to pass through the flow opening in the adjacent section.
 27. The method of claim 26, wherein the flow openings are formed before bending the sheet.
 28. A water heater for exchanging heat between hot gasses and water within the water heater, the water heater comprising: a water tank; a conduit for allowing flow of the gasses therethrough, the conduit extending vertically through the tank and promoting heat exchange between the gasses and water in the tank; and a baffle extending within the conduit for affecting the flow of the gasses, the baffle being operable to create a swirl-type flow of gasses through the conduit and including a sheet bent in a zig-zag manner, the sheet having a number of plate sections, each plate section having a through-flow portion allowing the gasses to flow therethrough, the sheet also having a number of first bends and a number of second bends, the first bends alternating with the second bends such that each plate section is defined between one first bend and one second bend, wherein all of the first bends and the second bends define substantially equal angles between adjacent plate sections, the angles being between about 50 degrees and about 80 degrees, and wherein the through-flow portion of one plate section is adjacent to one of the first bend and the second bend, and the through-flow portion of an adjacent plate section is adjacent to the other of the first bend and the second bend. 